Ingenious 'Row-bot' Devours Microbes From Polluted Water To Fuel Itself

Access to clean drinking water is something many of us take for granted. However, for millions of people living in developing nations, it is a scarce commodity. According to the World Health Organization 3.4 million people, mostly children, die annually from water-related diseases. But that could change soon thanks to 'Row-bot', a tiny autonomous robot that powers itself by eating harmful water microbes.

Inspired by the water boatman, a tiny aquatic insect that feeds off algae and dead plants as it skims along the water surface, Row-bot is the brainchild of University of Bristol Ph.D. student Hemma Philamore. Made from lightweight 3D printed composite material, the buoyant robot requires minimal energy to keep moving. This is important given that it is self-powered.

Photo Credit: University of Bristol

Similar to the aquatic insect, Row-bot ingests water through its 'mouth' as it glides over the water surface. A microbial fuel cell (MFC) inside its 'stomach' helps digest the bacteria in the water to produce an electric current that powers the robot.

Though that may sound magical, it is a natural reaction that occurs when MFC's consume sugars in an anaerobic environment.

Instead of releasing carbon dioxide and water like they would in a normal oxygen-filled environment, they release carbon dioxide, protons, and electrons.

The electrons are harnessed by a tiny 0.75 watt DC motor embedded inside to power the Row-bot. As it propels forward, it ingests additional bacteria-filled water, and the cycle continues.

The tiny bot's ability to not just clean the water, but also use the microbes to power itself is what is exciting researchers the most. Jonathan Rossiter, Professor of Robotics at Bristol University says, "The work shows a crucial step in the development of autonomous robots capable of long-term self-power. Most robots require recharging or refueling, often requiring human involvement."

The researchers who revealed the 'Row-bot' at the November 2015 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) held in Hamburg, Germany, believe that it has numerous potential uses. In addition to purifying the water in developing countries, Hemma Philamore thinks the robot would be tremendously helpful in environmental clean-ups following oil spills or algal blooms. It would even come in handy to monitor hazardous areas struck by natural or man-made disasters.

Photo Credit: University of Bristol

To prepare the autonomous robot to take on these important tasks, the researchers are working on a new prototype that will contain monitoring and control subsystems as well as additional switching circuitry - All, of course, will be powered by harmful water bacteria.